The present invention relates to an insulated roofing system including vents and a compressible seal. More particularly, this invention is for use with corrugated metal buildings and includes vents interposed between a metal roof and roof purlins that support the roof. Additionally, the roofing system includes compressible closure strips for use in sealing between a ridge vent and roofing panels having various corrugated contours.
Insulated roofing systems for use with building structures have been known for many years. It is well known to provide an insulation blanket beneath a metal roof. In a typical arrangement, the insulation is placed between the metal roof and a structural member, such as a Z-shaped steel purlin, in an effort to thermally insulate the interior of the structure from the thermally conductive metal roofing. Moreover, the need to insulate the interior of a structure having a thermally conductive metal roofing becomes especially important during a temperature extreme, such as a hot, sunny, summer day or a cold, windy, winter night. The need for insulation becomes even greater when the rising cost of utilities is considered, such as the cost of electricity required to run air conditioning units in order to cool the structure, and the cost of natural gas used by furnaces and the like, for the heating of the structure.
Traditional insulation for metal roofing has been carried out by placing a layer of thick roll insulation, such as fiberglass, beneath the roof. The insulation is supported by laying it over the top of roofing frame members or purlins that support the roofing system over the building structure. The roll insulating material should be of sufficient thickness to retard heat flow through the thermally conductive metallic roof. Unfortunately, in traditional roofing systems, the insulating material is often compressed between the sheet metal roofing and the purlin supports of the roofing system, resulting in a loss of thickness in the insulating material and consequently a reduction of the insulation efficiency of the insulation material.
In recent years, it has been attempted to solve the above problem of insulation material compression through the addition of an insulated block where the roof support contacts the metal roofing. Such an insulation block is shown in U.S. Pat. No. 4,651,489 to Hodges, et al., incorporated herein by reference. The rolled insulation may also be cut or positioned around the insulating block to prevent the rolled insulated material from being compressed, such as is shown in U.S. Pat. No. 4,346,543 to Wilson, et al. and U.S. Pat. No. 5,495,698 to Alderman, et al., both incorporated herein by reference. This helps the rolled insulating material to maintain a constant thickness throughout to provide an efficient insulation blanket. It has also been known to incorporate metallic spacers or brackets for reducing the compression of the insulation between a metal roof and roofing frame members as is shown in U.S. Pat. No. 3,394,516 to Taylor, et al. and U.S. Pat. No. 4,791,770 to Bell III, et al., both incorporated herein by reference.
Unfortunately, while this construction constitutes a considerable improvement in regard to the use and thermal efficiency of insulation in a roof structure, it is not without limitations. Moisture may become trapped in the space between the metal roof and the insulation when using prior art thermal insulation blocks as these blocks do not facilitate movement and removal of air from this space. Trapped moisture can have an extremely adverse effect on the thermal efficiency and life of the insulation material and may corrode the metal roof.
Additionally, in a roofing system as described above, the metallic roof will often be corrugated, having many peaks and valleys of various magnitudes. Typically, a ventilation system is mounted to the corrugated roof over an opening in the roof so that moisture and hot air may freely escape the roofing structure. The ventilation is often affixed to the upper portions or peaks of the corrugated roof. Often the ventilation material is relatively stiff and planar, thereby forming unprotected openings between the vent and roof wherever the contour of the corrugated roof descends from a peak. If left unprotected, moisture, debris and other contaminants may penetrate through these openings and enter the building. This problem has been addressed in recent years through the use of closure or sealing strips. However, because there are numerous corrugated roof configurations, the sealing strips must often be cut or formed to match the particular profile of the corrugated roof. Custom matching the sealing strips to the roof configuration increases the cost and makes it more difficult to stock sealing strips that will match a variety of corrugated roof configurations.
It is an object of the present invention to provide a roofing ventilation system for a metal building. Compressible closure strips are used to seal between corrugated sheet metal roofing and a roof vent of the system. Further, the present invention utilizes an insulating block located beneath the roof and having venting capability in order to allow moisture and hot air in the roofing system to escape.
In one embodiment of the present invention, the system includes a shield between the insulating vent block and insulation material, such that insulation adjacent a compressed area of material does not fluff or billow over air passages of the insulating block. This aids in keeping the vent unobstructed so that trapped moisture may be evacuated from the system.
A versatile sealing strip is provided in an embodiment of the present invention for sealing the area between a corrugated roof and the ventilation system regardless of the profile and shape of the corrugated roof. To these ends, a sealing strip formed from an open-celled foam material and having a plurality of slits allows for a good seal across the length of the roofing ventilation system. Further, the foam seal is sufficiently compressible in order to allow for a good seal at the highest peaks of the corrugated roof (where the distance between the roofing and the ventilation member is smallest), yet still reach the deepest valleys (where the distance between the roofing and ventilation member is greatest). The slits allow the foam seal to more readily mold itself to the contours of the corrugated roof surface, thereby increasing the effectiveness of the seal.
In an embodiment of the present invention, two ventilation strips are aligned along a ridge opening in the roof in an effort to vent air and evacuate moisture from the system that has transferred through one or more insulating vent blocks.
Further, it is the object of the present invention to provide protection to the inner building structure from the elements, helping to maintain a desirable temperature in the interior of the structure and further, keeping undesirable elements, such as rain, wind and snow, outside the structure.